SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89dd250ed0be1488c72725541837e980cc82ff6e091ecbb344e4786d9fe17576' 
  AND token = 'R0Hg61fWK0bHCfOBhjKAjg7yCbgvWkfKAA5Z3o5+JXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}